With the recent development of wireless communication technologies, data is increasingly exchanged through wireless devices. For example, users transmit and receive various data (for example, moving images, music, photos, documents, etc.) through wireless devices which can be accessed wirelessly, such as smart phones. The data exchanged through the wireless devices include not only data which is provided by service providers but also data which is transmitted to or received from other wireless devices. It is necessary to rapidly establish an initial connection among wireless devices to rapidly exchange data thereamong.